Antibiotics and macromolecular synthesis in microsomes and mitochondria: I. Antibiotics acting in the same manner in mitochondria and microsomes

Abstract

Effects of antibiotics were assayed on protein- and glycoprotein-synthesizing systems in isolated mitochondria and microsomes over a 10 5 concentration range. The antibiotic effects on glycoprotein synthesis were measured in isolated sterile rat liver and cortical intraneural mitochondria, while the effects on protein synthesis were measured in isolated sterile rat liver and cortical intraneural mitochondria and rat liver microsomes. The effects were all measured in ATP-supported systems and the microsomal system included pH 5 enzymes and GTP. Carbomycin, daunomycin, mitomycin C, oleandomycin, puromycin, streptomycin and vancomycin inhibited protein and glycoprotein synthesis in the mitochondrial system and protein synthesis in the microsomal system. Dactinomycin and oligomycin had no effect on either system. In general, the effects of the antibiotics caused a greater amount of inhibition of protein and glycoprotein synthesis in the cortical intraneural mitochondrial system than in the liver mitochondrial system. The protein synthesis was inhibited to a greater extent than the glycoprotein synthesis in both the liver and cortical intraneural mitochondrial systems.